Android上的文件存储:存储到sdCard
1.要向sdCard上写文件,必须要先判断手机内是否有sdCard。判断方法为:
if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
<span style="white-space:pre"> </span>File sdCardDir = Environment.getExternalStorageDirectory();//获取SDCard目录
<span style="white-space:pre"> </span>/**
<span style="white-space:pre"> </span>代码块
<span style="white-space:pre"> </span>**/
}
Environment.getExternalStorageState()方法用于获取SDCard的状态,如果手机装有SDCard,并且可以进行读写,那么方法返回的状态等于Environment.MEDIA_MOUNTED。
Environment.getExternalStorageDirectory()方法用于获取SDCard的目录。
2.使用FileOutputStream来实现写入数据
<span style="white-space:pre"> </span>File sdCardDir = Environment.getExternalStorageDirectory();
File saveFile = new File(sdCardDir, "wificontent.txt"); //在sdCard根目录下设置存储文件的文件名
try {
<span style="white-space:pre"> </span>FileOutputStream fileos = new FileOutputStream(saveFile);
fileos.write(wifi_save.getBytes()); //wifi_save是一个String字符串
fileos.close();
} catch (FileNotFoundException e) { //自动添加catch
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
3.在AndroidManefest.xml文件中添加权限
<span style="white-space:pre"> </span><!-- 在SDCard中创建与删除文件权限 -->
<span style="white-space:pre"> </span><uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<span style="white-space:pre"> </span><!-- 往SDCard写入数据权限 -->
<span style="white-space:pre"> </span><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>